History: Ashwagandha has been used in Ayurvedic medicine as a rasayana for 3000 years. The literal meaning of rasayana is “augmentation of rasa,” the vital fluid produced by the digestion of food. A more modern meaning of rasayana is “The science of Rejuvenation.” Ashwagandha in Sanskrit means “horse’s smell,” and is a reference to the scent of its root. The species name somnifera means “sleep-bearing” in Latin, a popular use of the herb.

Clinical Uses

Like many adaptogens, Ashwagandha is used as a tonic to support the functioning of the adrenal glands. Unlike most adaptogens, Ashwagandha is not stimulating, it’s a calming adaptogen. Studies and clinical experience show it is as potent as American or Chinese Ginseng, without the risk of overstimulation that can occur with excessive use of both Ginsengs. A true adaptogen, Ashwagandha helps balance people with elevated or low cortisol. By helping to reestablish normal cortisol rhythm, Ashwagandha is suited for use in all disorders where stress is a factor.

Ashwagandha is unique among adaptogens in that it has a nerve tonic effect, helping to increase your tolerance to stress that goes beyond what other adaptogens do. So it not only helps minimize excessive cortisol output from stress, it helps you perceive events as less stressful! It is an uplifting nerve tonic, so it is wonderful for depression, especially if the depression is stress induced.

Animal studies show that in large doses in mice, Ashwagandha directly increases the thyroid hormone T4. In massive doses it might be a thyroid stimulant, but in normal doses I think this is wishful thinking. It is however a good thyroid remedy. By balancing cortisol rhythm and suppressing elevated cortisol, Ashwagandha likely prevents the conversion of T4 to Reverse T3, an inactive form of thyroid hormone caused by excessive stress. In addition, both animal studies and clinical experience show that it helps to calm autoimmunity, the primary cause of hypothyroidism in America.

Ashwaghanda has chemo-preventive properties that make it a useful adjunct for patients undergoing radiation and chemotherapy. Its ability to boost white blood cell counts helps prevent the immune suppression so common with chemotherapy. When using Ashwagandha as an adjunct to chemo, I recommend making it as a decoction and combining it with codonopsis, astragalus and reishi.

Studies

A number of studies were done on Ashwagandha in the 1970’s and 1980’s that are not in English. Statistics from these studies are often quoted by authors when writing about Ashwagandha. However without access to the full text to review the details of the studies, I won’t mention them here.

There have been a number of animal studies on Ashwagandha that show its ability to decrease the stress response in mice. While this reinforces the traditional uses of Ashwagandha, the applications of animal studies to humans don’t always correlate and so are not included.

The following are human studies that show the efficacy of Ashwagandha. The study size in all of these trials were not large, but enough to justify the traditional uses of Ashwagandha.

Ashwagandha (300mg) taken over the course of 8 weeks in persons with anxiety disorders also given counselling (placebo also given counselling) noted that supplementation was associated with a 56.5% reduction in anxiety symptoms, while placebo only saw a 30.5% reduction.Naturopathic care for anxiety: a randomized controlled trial

The pharmacological activity of the root is attributed to the alkaloids and steroidal lactones

Twelve alkaloids, 35 withanolides and several sitoindosides have been isolated from Ashwagandha roots. The primary pharmacological activity of Ashwagandha has been attributed to two main withanolides, withaferin A and withanolide D, and an alkaloid, Somniferin, that exhibits some hypnotic properties.

Ashwagandha contains a relatively high amount of iron (320mcg/g), giving a standard dose around 1 mg of iron.

Dosage: The optimal dose is 3-6 grams a day as a water or milk decoction. However, both studies and my clinical use of Ashwagandha show that 500-1000mg of encapsulated Ashwagandha or 2-4ml of the tincture, taken two to three times a day works well.

Warnings: Ashwagandha has a history of use as a pregnancy tonic. However, reports of high doses being used to cause abortion in Africa are enough to warrant using extreme caution during pregnancy. People with severe hemochromatosis should avoid Ashwagandha because of the iron content. People that have a sensitivity to nightshade plants should avoid taking Ashwagandha.